Liquid ejection head, liquid ejection apparatus

Abstract

A liquid ejection head includes pressure generating chambers 11 , piezoelectric elements 17 , and a reservoir 22 . The reservoir 22 communicates with a plurality of ink inlets 21 a and 21 b . In a confluence area of liquid supplied through the ink inlets 21 a and 21 b , a wall opposite to the pressure generating chambers 11 projects to form a narrowed portion 22 a so that the width of this part is smaller than the width of the other parts.

1 . A liquid ejection head comprising:
 pressure generating chambers that marshal in a first substrate so as to be made to eject liquid through nozzle orifices by pressure variation; and   a reservoir that is provided in a second substrate so as to supply the liquid to the pressure generating chambers and to constitute a common liquid chamber provided in the direction in which the pressure generating chambers marshal;   the reservoir being supplied with the liquid through a plurality of liquid inlets, and   the reservoir's cross-sectional area, in a confluence area of the liquid supplied through the liquid inlets, being smaller than the reservoir's cross-sectional area in a predetermined area other than the confluence area.   
     
     
         2 . The liquid ejection head according to  claim 1 , the reservoir supplying the liquid to the pressure generating chambers through liquid supply ports in the direction along the surface of the second substrate, and an inner wall of the reservoir that faces the liquid supply ports in the confluence area projects toward the liquid supply ports. 
     
     
         3 . The liquid ejection head according to  claim 1 , the reservoir supplies the liquid to the pressure generating chambers through liquid supply ports in the direction of the thickness of the second substrate, and inner walls of the reservoir that extend with the liquid supply ports therebetween in the direction in which the pressure generating chambers are provided side by side, project toward each other in the confluence area. 
     
     
         4 . The liquid ejection head according to  claim 3 , both of the reservoir's inner walls, that extend with the liquid supply ports therebetween in the direction in which the pressure generating chambers marshal, are distant from the liquid supply ports by a distance larger than the maximum diameter of bubbles that can spontaneously disappear in the predetermined area. 
     
     
         5 . The liquid ejection head according to  claim 1 , at least one narrowed portion being formed in the confluence area. 
     
     
         6 . The liquid ejection head according to  claim 5 , the at least one narrowed portion having such a shape that the width gradually decreases in the direction in which the pressure generating chambers are provided side by side, from the sides of the liquid inlets toward the intermediate part between adjacent liquid inlets. 
     
     
         7 . The liquid ejection head according to  claim 5 , the width of the at least one narrowed portion gradually decreasing along the flow line of the liquid. 
     
     
         8 . The liquid ejection head according to  claim 5 , the at least one narrowed portion including a plurality of narrowed portions provided in the reservoir. 
     
     
         9 . A liquid ejection apparatus having the liquid ejection head according to  claim 1 .